Table 3.
Main sorghum transformation methods, explants, genotypes, selectable markers, optimizations, and Agrobacterium strains, when appropriate, adopted for improvements in tissue culture and transformation efficiency
| References | Explantsa | Genotypesa | Agrobacterium straina | SMa | Max. TE | Optimizations |
|---|---|---|---|---|---|---|
| Particle bombardment | ||||||
| Casas et al., (1993) | Immature embryos | P898012 | – | Bar | 0.29% | Genotypes (IS4225, CS3541, M91051, Tx430, P898012, P954035, SRN39, and Shanqui red) |
| Able et al., (2001) | Immature embryos | SA281 | – | Bar | 3 out of 4 tested events | Genotypes (M35-1, SA281, QL41, and P898012), explant (immature embryos and leaf segments), promoters (Act1, CaMV35S, and Ubi) and biolistic parameters (acceleration pressure, distance to target tissue from expulsion point, aperture of helium inlet valve) |
| Tadesse et al., (2003) | Immature embryos | Ethiopian accession ‘214856’ | – | Npt | 1.30% | Explants (immature and mature embryos, shoot tips, calli), promoters (Act1D, Adh1, CaMV35S, and Ubi1), selectable markers (Bar and Npt) and biolistics parameters (acceleration pressure, target distance, gap width and travel distance) |
| Casas et al., (1997) | Immature inflorescences | SRN39 | – | Bar | 2.61% | Genotypes (M91051, P898012, P954035, PP290, and SRN39), panicle length and biolistic parameters (particle size and material, DNA amount, acceleration pressure and target distance) |
| Grootbroom et al., (2008) | Immature embryos | P898012 | – | Pmi | 0.77% | Selectable markers (Bar and Pmi) |
| Raghuwanshi and Birch, (2010) | Immature embryos | Ramada | – | Hpt | 0.09% | Genotypes (32 sweet sorghum), tissue culture media composition (increase of cytokinin), selectable markers (Hpt and NptII) |
| Liu and Godwin, (2012) | Immature embryos | Tx430 | – | NptII | 20.70% | Tissue culture media composition and biolistics parameters |
| Brandão et al., (2012) | Immature inflorescences | CMSXS102B | – | Bar | 3.33% | Genotypes (nine accessions from Embrapa Maize and Sorghum National Research Center, Brazil), explant developmental stages (3–5cm in length), biolistics parameters (in osmotic medium, acceleration pressure, microcarriers flying distance) |
| Visarada et al., (2014) | Immature embryos | CS3541 and 296B | – | Bar | 0.25% | Delivery method (Agrobacterium and particle bombardment), explant size, post-bombardment treatments |
| Belide et al., (2017) | Immature embryos | Tx430 | – | NptII | 46.60% | Tissue culture media composition (addition of lipoic acid), explant size, selectable markers (Bar and NptII), method of subculture post-bombardment |
| Silva et al., (2020) | Leaf whorls | Tx430 | – | NptII | All 7 tested events | Genotypes (Tx430 and P898012) and tissue culture media composition (addition of activated charcoal and polyvinylpyrrolidone) |
| Agrobacterium-mediated transformation | ||||||
| Zhao et al., (2000) | Immature embryos | P898012 | LBA4404 | Bar | 10.10% | Genotypes (P898012 and PHI391), source of explant (grown in the field or greenhouse), tissue culture conditions and media composition |
| Carvalho et al., (2004) | Immature embryos | P898012 | LBA4404 | Hpt | 3.50% | Genotypes (Feterita Gesish, P898012, P967083, IS2329, Rio, Sugar drip, B-Wheatland, RTx430, and Candystripe), embryo selection, tissue culture media composition, tissue culture conditions, Agrobacterium inoculation methods |
| Gao et al., (2005) | Immature embryos | C401 | EHA101 | Pmi | 3.30% | Genotypes (C401 and Pioneer 8505), tissue culture media composition |
| Howe et al. (2006) | Immature embryos | C2-97 | NTL4 | NptII | 4.50% | Genotypes (Tx430 and C2-97), Agrobacterium strains (C58C1, LBA4404, EHA101, C58, and NTL4), selection agent (geneticin and paromomycin) |
| Nguyen et al., (2007) | Immature embryos | Sensako 85/1191 | LBA4404 | Hpt | 5.00% | Explant pre-treatment, tissue culture conditions and media composition |
| Gurel et al., (2009) | Immature embryos | P898012 | LBA4404 | Pmi | 8.30% | Genotypes (P898012, Tx430, 296B, and C401), explant pre-treatmemt, Agrobacterium strains (EHA101 and LBA4404), tissue culture media composition |
| Visarada et al., (2014) | Immature embryos and shoot buds | CS3541 and 296B | EHA105 | Bar | 0.23% | Delivery method (Agrobacterium and particle bombardment), explant type (shoot buds and immature embryos), decontamination treatments for removal of Agrobacterium |
| Wu et al., (2014) | Immature embryos | Tx430 | AGL1 | Pmi | 33.20% | Agrobacterium strains (AGL1 and LBA4404), selectable markers (PAT and Pmi), tissue culture media composition (increased copper sulfate and plant hormone BAP) |
| Yellisetty et al., (2015) | Shoot apical meristem | SPV462 | LBA4404 | Hpt | 36%b | In planta method development |
| Do et al., (2016) | Immature embryos | P898012 | AGL1 | Bar | 14.20% | Genotypes (P898012, TBx623, Tx2737, Tx430, and Wheatland), Agrobacterium strains (AGL1, EHA101, and GV3101), promoters (CaMV35S, MAS, and Ubi), tissue culture conditions |
| Sato-Izawa et al., (2018) | Immature embryos | Tx430 | GV2260 | Hpt | 1.90% | Explant pre-treatment and size |
Selectable markers (SM): Bar, Bialaphos resistance; Hpt, Hygromycin phosphotransferase; Npt, Neomycin phosphotransferase; PAT, Phosphinothricin acetyltransferase; Pmi, Phosphomannose isomerase. Promoters: Act1D, Actin 1D; Adh1, Alcohol dehydrogenase isozyme 1; CaMV35S, Cauliflower mosaic virus 35S; MAS, Mannopine synthase; Ubi, Ubiquitin. Max. TE: maximum transformation efficiency. TE is generally defined as the total number of independent events regenerated divided by the total number of transformed explants, although it can be omitted or vary depending on the publication.
Results from the most successful transformations or optimized conditions.
Results from T1 from selected positive T0 plants.